London, Dec 29 : South Africa -- one of the epicentres of the Omicron variant -- has seen a drop of about 40 per cent in new cases of Covid infection, suggesting that the new variant could be less severe than Delta. The seven day rolling average for new infections plummeted by 35 per cent from an all-time high of 23,000 cases nine days ago to 15,000 on Monday, The Telegraph reported. While the new data must be taken with caution, experts assert that it is clear that the country has passed its Omicron peak with "substantially lower" death rates than with the Delta variant. However, experts also warned against applying South Africa's data to other countries. It is because the South African population suffered devastating Beta and Delta variant waves, which has given them high levels of immunity. "We should interpret the data from South Africa with a lot of caution. This is early days and public health practice is local," John Nkengasong, director of the Africa CDC, was quoted as saying. "This data confirms what the scientists in South Africa have been saying for a few weeks, that this is a variant which is more transmissible, making people more likely to catch it, but that the symptoms and the impact of it are less severe," Jamie Jenkins, former head of health analysis at the UK's Office for National Statistics, was quoted as saying by Daily Mail. "We are seeing far fewer deaths than we have in the past," Jenkins added. Last week new data from South Africa showed nine in 10 deaths from Omicron were in unvaccinated patients. Among the country's 309 deaths from the variant, just 40 were found to be in people given two vaccine doses, illustrating the crucial protection provided by being jabbed, the report said. Meanwhile, the World Health Organisation (WHO), in its latest weekly epidemiological update on Tuesday, warned that the overall risk associated with the Omicron variant remains 'very high' which could cause widespread disruption to health systems and other critical services. "Consistent evidence shows that the Omicron variant has a growth advantage over the Delta variant with a doubling time of two to three days," the WHO said. The warning comes as the new Omicron variant in the US has driven daily Covid-19 new cases to a record high of over 510,000. It is the highest single-day increase of cases since the onset of the pandemic in the country, according to the latest data from Johns Hopkins University. Besides, the variant has also soared Covid cases in a number of European countries such as the UK, France, Portugal and Ireland, as well in India. /IANS